X. Development of Best Formulation and Utilization of
Figure 18. Ripened croton seeds (A), grounded (B), fine textured grounded seeds (C) and weighed grounded seeds (D).
• Activity II. Method of application of formulated C. tiglium as seed protection against storage insect pests. Empty sacks labeled with permanent ink pilot pentel pen were treated with the three different dosages of C. tiglium in soaked and sprayed methods of application (Figure 19). The control treatments were applied with water alone.
Figure 19. Empty sacks soaked (A), and Sprayed with the different dosages of C. tiglium (B).
After the treatment application, the 18 empty sacks were air dried, filled with 10 kilograms rice seeds and placed inside the screen cage (Figure 20) at PhilRice Agusan warehouse.
A B
C D
A B
Figure 20. Treated sacks placed inside the screen cage in the warehouse to protect from rats damages.
• Activity III. Dosage/rate determination for maximum utilization of C. tiglium as seed protection against storage insect pests.
Three different dosages, 25g, 50g and 100g of powered croton seeds mixed with 1 liter of water were prepared prior to the application into the seed sacks in the warehouse of PhilRice Agusan.
• January to June 2014 Insect Density (Ave. no.). There were five common stored grain insect pests recorded during the data collection. These include the Lesser Grain Borer (Rhyzoppertha dominica), Rice Weevil (Sitophilus oryzae), Red Flour Beetle (Tribolium castaneum), Flat Grain Beetle (Cryptolestes pusillus) and Saw Toothed Grain Beetle (Oryzaephilus sarinamensis) (Figure 21). Occurrences of unidentified species of parasitoids were also noticed from seed samples. Generally, lower average number of stored insects’
was recorded from those sacks soaked in croton solutions at 1.5 to 6 months after application. It was further noted that those sacks applied with 100 grams croton solutions have lower stored insect population than those sacks applied with 50, 25 grams, and the control treatment, respectively. At 1.5 months after application, those sacks soaked in 100 grams croton solution have 18.67 adult stored insects significantly lower to those sacks soaked in 25 grams but comparable 50 grams and the control treatment.
Figure 21. Adult Lesser grain borer (a), Rice weevil (b), Red flour beetle (c), Flat grain borer (d), Saw toothed beetle (e), and unidentified adult parasitoid
(f).
Table 47. Mean number of adult storage insect pests from 1.5 to 6 months after the application of different dosages of C. tiglium botanical solutions.
January to June 2014.
Treatment
Month After Treatment
1.5 3 4.5 6
Sprayed Soaked Sprayed Soaked Sprayed Soaked Sprayed Soaked Control 26.67ns 22.67ab 40.33
ns 37.00ns 69.00ns 75.33ns 62.00ns 68.00ns 25g 29.67 42.33a 47.33 38.00 67.00 48.33 43.33 46.00 50g 34.33 27.33ab 53.67 33.67 65.33 47.33 42.00 45.67 100g 26.67 18.67b 37.00 25.33 81.00 44.00 39.33 44.00 Average of 3 replications
1/ Based on 500g seed samples
Values followed with different letters are significantly different at á=0.05 based on Fisher’s PLSD test.
Table 48. Percentage of storage insect pests survived from 1.5 to 6 months after the application of different dosages of C. tiglium botanical solutions.
January to June 2014.
Treatment Month After Treatment
1.5 3 4.5 6
Sprayed Soaked Sprayed Soaked Sprayed Soaked Sprayed Soaked Control 90.65a 95.48a 86.43ns 90.45ns 73.66ns 64.05ns 74.17ns 69.50ns 25g 48.95b 55.17b 64.02 86.64 69.45 66.03 63.07 53.52 50g 33.82bc 25.85c 77.15 89.76 65.36 75.15 59.21 56.05 100g 20.38c 24.34cd 71.33 72.43 51.66 60.41 54.08 55.45 Average of 3 replications
1/ Based on dead insects from 500g seed samples
Values followed with different letters are significantly different at á=0.05 based on Fisher’s PLSD test.
• Insect Survival (%). The percentage of insect survival or alive stored insect pests depended on the concentration of croton solutions and span of exposure. Percentage survival decreased as concentration used increased. These were noticed at 1.5 months after application were sacks sprayed with 100 g solutions have the lowest (20.38%) alive stored insect recorded. It was comparable to those sacks sprayed with 50g (33.82%) but significantly lower to 25g and the control treatment respectively. Similar trend were noticed in soaked method wherein those sacks soaked in 100g have the lowest alive stored insects recorded. Survival increases from 3 to 6 months after the application, yet, those sacks applied with 100g croton solutions have usually lower alive insects recorded.
This is in connection with the findings of Kemabonta et al.
(2013) that percentage mortality of S. oryzea depended on the plant products concentration of formulation and exposure time. In wheat grains treated A. indica powder, mortality for all treatment was significantly higher than the control at P<0.05.
Highest (100g) dosage seemed to kill more stored insects over time. As evidence, dead insects were collected and recorded during data collection. Most of them were the lesser grain borer that seemed vulnerable to croton solutions while the slight affected were the rice weevils.
• Damaged Grains (%). Stored grains like rice seeds that were not properly protected would lose its quality over time due to the damaged caused by stored insect pests in the warehouse.
Percentages of grain damaged were presented in table 3. At 1.5 months after application, sacks soaked in 50g botanical solutions obtained 0.07% grain damaged and significantly lower than the control (39.67%) but comparable those sacks sprayed with 25 and 100g, respectively. At 3 months after application, those sacks sprayed and soaked in 100g croton solutions had the lowest (1.33 & 0.20%) grains damages but comparable to 50 and 25 grams respectively. The control have the highest damaged. At 4.5 to 6 months after application, those sacks treated with 100g croton solutions continually obtained lower grain damaged than those applied with 50 and 25g, respectively. The results further showed that soaked method have a little bit lower percentage of grain damaged than sprayed method.
Table 49. Percentage of damaged grains from 1.5 to 6 months after the application of different dosages of C. tiglium botanical solutions. January to June 2014.
Treatment Month After Treatment
1.5 3 4.5 6
Sprayed Soaked Sprayed Soaked Sprayed Soaked Sprayed Soaked Control 3.33ns 0.67a 7.67a 0.93a 2.93a 2.63a 2.20a 2.23a 25g 1.67 0.23b 4.00ab 0.57b 1.93b 2.16b 1.80ab 1.77ab 50g 0.67 0.07b 4.00ab 0.30bc 1.53b 1.60c 1.03b 0.97ab 100g 0.00 0.10b 1.33b 0.20c 1.36b 1.13d 0.97b 0.80b Average of 3 replications
1/ Based on 1000 seed samples
Values followed with different letters are significantly different at á=0.05 based on Fisher’s PLSD test.
• Seed Germination (%). Seed germination is one of the factors considered after seed storing. Based on the standard, it should fall below 85 percent. The present study showed that percentage of seed germination from the four treatments did not showed significant differences from 1.5 up to 4.5 months after the application of croton botanical solutions. Though there were small variations noticed but still and did not fall below 88 percent. It was further noticed that at 6 months after application, all treatments in sprayed method continue to decline ranging from 86 to 89.67%, respectively. In soaked method, germination ranging from 91.33 to 96.67 percent, respectively. The results suggest that 6 months duration of seed storing, the seeds still possessed a good germination.
Table 50. Percentage of seed germination1/ from 1.5 to 6 months after the application of different dosages of C. tiglium botanical solutions. January to June 2014.
Treatment Month After Treatment
1.5 3 4.5 6
Sprayed Soaked Sprayed Soaked Sprayed Soaked Sprayed Soaked Control 94.00ns 97.67ns 95.33ns 91.67ns 95.33ns 91.67ns 89.67ns 96.67a 25g 97.67 97.33 88.33 90.00 88.33 90.00 89.33 93.33ab 50g 92.33 94.00 90.67 88.67 90.67 88.67 88.00 93.00ab 100g 95.33 94.33 91.67 91.33 91.67 94.67 86.33 91.33b Average of 3 replications
1/ Based on 100 seed samples
Values followed with different letters are significantly different at á=0.05 based on Fisher’s PLSD test.
• Weight of 1000 grains (grams). Stored grain insects often cause reductions in germination and weight as a result of direct feeding. Most of the treatments did not showed significant differences after 6 months except in sprayed method at 3 months. Sacks sprayed with 50g had the lowest
(23.57g) weight among the treatments but it was comparable to 25 and 100g respectively. The control had the heavier (24.27g) weights of 1000 grains. One thousand grain weight ranges from 23.57 to 24.77g, respectively. Variation in grain weights maybe due to damage grains and half-filled grains incorporated unintentionally during the counting of 1000 grains.
Table 51. Weight of 1000 grains from 1.5 to 6 months after the application of the different dosages of C. tiglium botanical solutions. January to June 2014.
Treatment Month After Treatment
1.5 3 4.5 6
Sprayed Soaked Sprayed Soaked Sprayed Soaked Sprayed Soaked Control 24.27ns 24.17ns 24.07a 24.10ns 24.43ns 24.10ns 24.03ns 25.13ns 25g 24.30 24.07 24.00ab 24.13 23.47 24.67 24.33 24.23 50g 24.47 24.30 24.23b 24.30 24.57 24.77 24.63 24.43 100g 24.60 24.87 24.37ab 24.34 24.60 24.80 24.70 24.33 Average of 3 replications
Values followed with different letters are significantly different at á=0.05 based on Fisher’s PLSD test.